1. Field of the Invention
This invention relates to real time, two-dimensional video data processing. In particular, it relates to pictorial edge detection and processing systems.
2. Description of the Prior Art
Digital machines have been used to select and expand the dynamic range of selected grey levels within video data. See e.g., U.S. Pat. No. 3,988,602. Digital machines have also been used to normalize the background brightness level in video data, to identify and select features according to their grey level relative to a local background, (U.S. Pat. No. 3,621,129), and to normalize the brightness level of each picture element with respect to the average brightness of the surrounding pictorial elements (U.S. Pat. No. 3,996,421). A few machines of the prior art operate in real time.